2003 HONDA CIVIC air intake

Intake Air System
Component Location Index
INTAKE AIR BYPASS CONTROLTHERMAL VALVETest, page 1'1-161
i l.
AIR CLEANERReplacement, page 1 1'162AIR CLEANER ELEMENTReplacement, page 1 1-162
THROTTLE CABLEAdjustment, page 1 1-163Removal/lnstallation, page 1 1-164THROTTLE BODYTest, page l'l-160Removal/lnstallation, page 1 1-165Disassembly/Reassembly, page 1 1 166
11-159

Intake Air System
Throttle Body Test
NOTE:. Do not adjust the throttle stop screw. lt is preset at the
factory.. lf the malfunction indicator lamp (MlL) has been
reported on, check for diagnostic trouble codes(DLCS) (see page 11 3).
1. With the engine off, check the throttle cable
movement. The cable should move without binding
or sticking.
. lf lhe cable moves OK, goto step 2.. lf the cable binds or sticks, check it and its routing.. lf the cable isfaulty, reroute itor replace itand
adjust it (see page 11-163), then go to step 2.
2. l\4ove the throttle lever by hand to see if the throftle
valve and/or shaft are too loose or too tight.
. lf there is excessive play in the throttle valve
shaft, or any binding in the throttle valve at the
fully closed position, replace the throttle body.. lf thethrottlevalve and shaft are OK, goto step3.
3. Connect the scan toolto the DLC.
Turn the ignition switch ON (ll).
Check the throttle position with the scan tool. The
reading should be about 10% when the throttle is
fully closed and about 90% when the throttle is fully
openeo.
. lf the throttle position is correct, the throttle body
is OK.. lf thethrottle position is notcorrect, replace the
throttle body.
5.
11-160
!

Intake Air Bypass GontrolThermalValve Test
Special Tools Required
Vacuum Pump/Gauge,0 30 in. Hg A973X-041-XXXXX
1. Stan the engine. Then let it idl€.
NOTE: The engine coolant temperature must be
below 149'F (65'C).
2. Remove the vacuum hose (A)from the intake air
duct, and connect a vacuum pump/gauge to the
nose.
3. Raise and lowerthe engine speed. and make sure
the vacuum gauge reading changes as the engine
speeo cnanges.
lf the vacuum reading does not change, check for
these problems:
. Misrouted, leaking, broken, or clogged intake air
bypass control system vacuum lines.. A cracked or damaged intake air bypass control
thermal valve.
4. Hold the engine at 3,000 rpm with no load (in
neutral) until the radiator fan comes on, then let it
id le.
5. Raise and lower the engine speed, and make sure
the vacuum gauge reading does not change as the
rpm cnanges.
lf the vacuum reading changes, check for these
proorems:
. l\4isrouted, leaking, broken, or clogged intake air
bypass control system vacuum lines.. A cracked or damaged intake air bypass control
thermal valve.
11-161

Intake Air System
1. Remove the nuts (A) and the stud (B).
Air Cleaner Replacement
Remove the air cleaner (C).
Install in the reverse order of removal.
2.
3.
11-162
Air Cleaner Element Replacement
1. Disconnect the PCV hose 1A).
Open the air cleaner housing cover (B).
Remove the air cleaner (C) from the air cleaner
housing (D).
Install in the reverse order of removal.
2.
3.\,
4.
{0.3 kgf m,2lbf.ft)

Intake Air System
Throttle Cable Removal/lnstallation
1. Fully open the throttle valve, then remove the
throttle cable (A) from the throttle link (B).
Remove the cable housing (C)from the cable
bracket (D).
Remove the throttle cable (A)from the accelerator
pedal (B).
2.
3.
SILICONE GREASE B(P/N 08798-9002)
(P/N 08?98-9002)
11-164
5.
Install in the reverse order of removal.
After installing, start the engine. Hold the engine at
3,000 rpm with no load (in neutral) untilthe radiator
fan comes on, then let it idle.
Hold the cable, removing all slack from it.
Set the locknut on the cable bracket {A).Turn the adjusting nut (B) so that its free play is
0 mm.
The should beno crearance.
Remove the cable from the cable bracket (A). Set
the adjusting nut on the other side of the throttle
bracket, then tighten the locknut {C}.
With the cable properly adjusted, check the throttle
valve to be sure it opens fully when you push the
accelerator pedal to the floor. Also check the
throttle valve to be sure it returns to the idle
position whenever you release the accelerator
Deoat.
7.
!
8.
9.
('1.0 kgf.m,7.2 tbf.ftl

Intake Air System
Throttle Body Disassembly/Reassembly
EVAPORATIVE EMISSION {EVAP)CANISTER PURGE VALVE
A
V
2 N.m{0.2 kgt m, 1 lbf.ft)
3.5 N.m(0.35 kgf m.2.5lbf ft)
MAP SENSOR
THROTTLE BODY
L
TP SENSOR
11-166

Slave Cylinder Replacement
NOTE:. Use fender covers to avoid damaging painted
surfaces.. Do not spill brake fluid on the vehicle; it may damage
the paint; if brake fluid does contact the paint, wash it
off immediately with water.
1. Write down the frequencies for the radio's preset
buttons. Disconnect the negative ( ) cable first,
then the positive (+)cable from the battery.
Remove the battery.
2. Remove the battery tray.
a
Remove the air cleaner housing cover and the air
cleaner housing (see step 6 on page 5-2).
Remove the intake air duct (see step 8 on page 5-3) .
Remove the clutch line bracket (A).
4.
5.
6. Remove the mounting bolts (A) andtheslave
cylinder (B).
Remove the roll pins (C). Disconnect the clutch line(D), and remove the O-ring (E). Plug the end of the
clutch line with a shop towel to prevent brake fluid
f rom coming out.
Installthe slave cylinder in the reverse order of
removal. Install a new O-ring (A).
7.
,,6NJ'
=--#.q!4sEn(P/N 08798-90021
9.
(Brak6 Assembly Lube)
Pullthe boot (B) back, and apply brake assembly
lube to the boot and slave cylinder rod (C). Reinstall
the boot.
Apply super high temp urea grease (P/N 08798-
9002) to the push rod of the slave cylinder. Tighten
the slave cylinder mounting bolts to 22 N m (2.2
kgf m, 16lbf.ft).
(cont'd)
12-7
10.

Clutch
Slave Cylinder Replacement (cont'd)
11. Bleed the clutch hydraulic system.
. Aftach a hose to the bleeder screw (A), and
suspend the hose in a container of brake fluid.. Make sure there is an adequate supply offluid in
the clutch master cylinder, then slowly pump the
clutch pedal until no more bubbles appear atthe
bleeder hose.. lt may be necessary to llmit the movement of the
release fork (B) with a block of wood to remove
all the air from the system.. Tighten the bleed screw to I N.m (0.8 kgf.m, 6 lbf
ft); do not ovenighten it,. Refill the clutch master cylinder with fluid when
done.. Always use only Honda DOT 3 brake fluid.
Install the intake air duct (see step 36 on page 5-14).
Installthe air cleaner housing (see step 37 on page
5-15).
Install the battery tray.
Install the battery, connect the positive (+) cable
first, then the negative (- ) cable.
Reset the frequencies for the radio station preset
buttons,
12.
13.
14.
t5.
16.
12-8
L